Clinical Prognosis of Vocal Cord Paralysis After Cardiothoracic Surgery in Infants

We aimed to clarify the long-term outcomes and prognosis of vocal cord paralysis (VCP) after cardiothoracic surgery in infants as well as the usefulness of laryngeal ultrasound (LUS) as screening for VCP. Overall, 967 infants aged 1-year-old or younger who underwent cardiothoracic surgery between 2008 and 2022 were included in this study. We divided the patients into two groups based on the period on whether they underwent screening without or with LUS and compared the incidence of VCP between the groups. There were no differences in the patients' preoperative characteristics between the two periods, whereas the incidence of VCP was significantly higher in period 2 than in period 1 (11.0% vs. 3.2%, p < 0.0001). The incidence of VCP among the procedures, including aortic arch repair, was > 50% and significantly increased from period 1 to period 2. The sensitivity and specificity of LUS was 87% and 90%, respectively. Symptoms of VCP improved in 92% of patients. Repeated flexible laryngoscopy revealed that the residual rate of VCP was 68%, 52%, and 48% at 6, 12, and 24 months, respectively. In conclusion, symptoms of postoperative VCP improved in most cases; however, paralysis persisted in half of the patients. As a screening method, LUS is useful for evaluating postoperative VCP. A more accurate understanding of VCP is needed to improve postoperative outcomes.

Diagnostic Accuracy of Laryngeal Ultrasound for Evaluating Vocal Fold Movement Impairment in Children

PURPOSE

Vocal fold movement impairment (VFMI) secondary to recurrent laryngeal nerve (RLN) injury is a common source of morbidity after pediatric cervical, thoracic, and cardiac procedures. Flexible laryngoscopy (FL) is the gold standard to diagnose VFMI yet can be challenging to perform and/or risks possible clinical decompensation in some children and is an aerosolizing procedure. Laryngeal ultrasound (LUS) is a potential non-invasive alternative, but limited data exists in the pediatric surgical population regarding its efficacy. We aimed to investigate the diagnostic accuracy of LUS compared to FL in evaluating VFMI.

METHODS

A prospective, single-center, single-blinded (rater) cohort study was undertaken on perioperative pediatric patients at risk for RLN injury. Patients underwent FL and LUS. Cohen's kappa was used to determine chance-corrected agreement.

RESULTS

Between 2021 and 2023, 85 paired evaluations were performed with patients having a median (IQR) age of 10 (4, 42) months and weight of 7.5 (5.4, 13.4) kilograms. The prevalence of VFMI was 27.1%. Absolute agreement between evaluations was 98.8% (kappa 0.97, 95% CI: 0.91-1.00, P < 0.001). The sensitivity and specificity of LUS in detecting VFMI was 95.7% and 100%, yielding a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 98.4% (95% CI: 90-100%). Diagnostic accuracy was 98.8% (95% CI: 93-100%).

CONCLUSION

LUS is a highly accurate modality in evaluating VFMI in children. While FL remains the gold standard for diagnosis, LUS offers a low-risk screening modality for children at risk for VFMI such that only those with an abnormal LUS or presence of clinical symptoms discordant with LUS findings should undergo FL.

TYPE OF STUDY

Prospective, single-center, single blinded (rater), cohort study.

LEVEL OF EVIDENCE

Level II.

Feasibility and accuracy of laryngeal ultrasound for the assessment of vocal cord mobility in children

OBJECTIVE

Transcutaneous laryngeal ultrasonography has been utilized to document vocal cord mobility in the adult perioperative thyroidectomy setting with variable success. The aims of this study were to assess the feasibility of using transcutaneous ultrasound in vocal cord visualization in children, to determine the accuracy in detecting vocal cord immobility compare to flexible laryngoscopy, and to identify any barriers that may affect its utility.

METHODS

This is a prospective blinded-assessor study. Transcutaneous laryngeal ultrasound and flexible laryngoscopy were performed in two pediatric settings: perioperative thyroid surgery and inpatient consultation for airway, voice, or swallowing concerns. The video recordings of ultrasound and laryngoscopy were assessed by two fellowship-trained pediatric otolaryngologists independently.

RESULTS

A total of 83 paired laryngoscopy and ultrasound assessments were performed, 39 for perioperative thyroidectomy and 44 for inpatient consultation. The majority had normal vocal cord mobility (65/83, 78%), while 16 had unilateral cord palsy and 2 had bilateral palsy. The vocal cords were successfully visualized on ultrasound in 82/83 (99%) evaluations. Compared to gold standard laryngoscopy, the sensitivity for diagnosing vocal cord palsy on ultrasound was 53-83%, and the specificity was 97-98%. The sensitivity for detecting asymmetric vocal cord movement was 56-88%, and the specificity was 99%. The agreement between ultrasound and laryngoscopy diagnoses were 87-94% (κ = 0.58-0.83, moderate to near perfect agreement). The intra-rater agreement was 95-100% (κ = 0.64-1.0), and inter-rater agreement was 90% (κ = 0.66). Both subjects with bilateral vocal cord palsy had incorrect ultrasound diagnoses by both observers.

CONCLUSION

We were able to utilize transcutaneous laryngeal ultrasound to successfully visualize vocal cord mobility in almost all pediatric patients with a high degree of specificity. The modality has limitations in the assessment of bilateral vocal cord palsy, and its sensitivity was observer-dependent.

The utility of handheld ultrasound as a point-of-care screening tool to assess vocal fold impairment following congenital heart surgery

INTRODUCTION

Vocal fold motion impairment (VFMI) is a known potential complication of congenital heart surgery (CHS). Flexible nasolaryngoscopy (FNL) is the gold standard for evaluation of vocal fold movement but has risks, including epistaxis, desaturation, and changes in heart rate. Laryngeal ultrasound (LUS) has begun to emerge as a diagnostic tool and has been shown to have high accuracy in the evaluation of VFMI. We sought to assess the utility of hand-held LUS as a point-of-care screening tool to assess VFMI in pediatric patients following congenital heart surgery.

METHODS

Using a prospective cohort design, children under 18 years who were undergoing congenital heart surgery at a tertiary care pediatric hospital were enrolled. All patients underwent postoperative LUS and FNL. All studies were reviewed by two otolaryngology reviewers blinded to the clinical diagnosis. Higher quality studies were reviewed by two cardiology reviewers also blinded to the clinical diagnosis. Accuracy and inter-rater reliability were calculated.

RESULTS

Sixty-two children were screened. Fourteen children with VFMI were identified via FNL. When comparing LUS and FNL, both individual accuracy (90.3% and 75.8%) and interrater agreement (79% overall, 96% for high quality videos) were high for the otolaryngology reviewers. The cardiology reviewers were able to obtain 100% accuracy for high quality videos.

CONCLUSION

Handheld LUS has utility as a point-of-care screening tool to assess VFMI. This may have benefit in low-resource settings, for universal screening in cardiac intensive care units, or in settings where otolaryngology consultation may be difficult to obtain.

Point of care, clinician-performed laryngeal ultrasound and pediatric vocal fold movement impairment

INTRODUCTION

Vocal fold movement impairment (VFMI) is a well-known sequela of cervical and thoracic procedures performed in the vicinity of the recurrent laryngeal nerve. Interpretation of flexible nasolaryngoscopy (FNL) can be difficult in young children due to crying, secretions, and obstructing supraglottic structures. We have previously published on the use of radiologist performed and interpreted, laryngeal ultrasound (LUS) to evaluate vocal fold mobility with substantial agreement with FNL in infants in the cardiovascular intensive care unit. The purpose of this study was to evaluate point of care, clinician performed, LUS for vocal fold mobility in a pediatric voice clinic.

METHODS

LUS and FNL were performed and recorded on 30 consecutive patients (11 with a clinical diagnosis of VFMI and 19 with clinically normal mobility) in a pediatric voice clinic. All LUS was performed by a single clinician (reviewer 1) with a GE logiq P9 and 12 MHz linear probe. Deidentified recordings of the LUS and FNL (without sound) were reviewed in random order by 2 fellowship trained pediatric otolaryngologists who were blinded to the vocal fold mobility. Cohen's kappa was used to determine agreement.

RESULTS

There was substantial agreement (κ  = 0.7) between the reviewers regarding interpretation of LUS as well as regarding interpretation of FNL κ  = 0.7802. In addition, each reviewer had near perfect to substantial agreement between their interpretation of the LUS and FNL (reviewer 1 κ  = 0.9294 and reviewer 2 κ  = 0.8413).

CONCLUSION

Point of care, clinician performed, LUS can be used for the identification of VFMI with substantial agreement with FNL with good inter-rater reliability. This provides clinicians with another tool in their armamentarium for the evaluation of challenging larynges.